This invention relates to apparatus for mixing and spraying a mixture of the two parts of a resin system and a fiber onto a surface.
The art is replete with a variety of spray guns that can either be combined with, or have as integral subassemblies thereof, choppers to cut fiberglass roving into short lengths for combination with the sprayed on resin to form a fiberglass reinforced plastic layer. Reference can be made to U.S. Pat. No. 4,081,904 to Krohn, et al., which discusses several different types of such spray guns. However, these fibers do not need to be of precisely controlled lengths nor do they need to be of particularly uniform distribution in the resulting layer. Also, these sprayers combine the fibers with the resin after the two parts of the resin have been mixed and downstream of the exit nozzle of the spray gun. If a very fine fiber were to be introduced into the spray gun upstream of its internal mixing means, it would either clog the spray gun or break up the small fibers and randomize their length distribution in the resulting sprayed on layer. There is no known spray gun apparatus that can apply the resin/fiber system contemplated herein while retaining the desirable length distribution of the fibers in the applied layer.